Noblesse oblige. There are obligations to nobility. Comte de Laborde, in a notice to the French Historical Society in 1865, attributes the phrase to Duc de Levis, who used it in 1808, apropos of the establishment of the nobility.

This was the noblest Roman of them all:All the conspirators save only heDid that they did in envy of great Cæsar;He only, in a general honest thoughtAnd common good to all, made one of them.Julius Cæsar. Act V. Sc. 5. L. 68.